Place value

problem

More Mathematical Mysteries

Age

11 to 14

Challenge level

1 out of 3

Write down a three-digit number Change the order of the digits to get a different number Find the difference between the two three digit numbers Follow the rest of the instructions then try to explain why this works.
problem

Not a Polite Question

Age

11 to 14

Challenge level

2 out of 3

When asked how old she was, the teacher replied: My age in years is not prime but odd and when reversed and added to my age you have a perfect square...
problem

Writ Large

Age

11 to 14

Challenge level

2 out of 3

Suppose you had to begin the never ending task of writing out the natural numbers: 1, 2, 3, 4, 5.... and so on. What would be the 1000th digit you would write down.
problem

Eleven

Age

11 to 14

Challenge level

2 out of 3

Replace each letter with a digit to make this addition correct.
problem

Back of the Queue

Age

11 to 14

Challenge level

2 out of 3

Weekly Problem 48 - 2013
What is the remainder when the number 743589 × 301647 is divided by 5?
problem

So Many Sums

Age

11 to 14

Challenge level

2 out of 3

In this addition each letter stands for a different digit, with S standing for 3. What is the value of YxO?
problem

Kangaroo Subtraction

Age

11 to 14

Challenge level

2 out of 3

Can you solve this 'KANGAROO' alphanumeric subtraction?
problem

Halfway

Age

11 to 14

Challenge level

2 out of 3

Can you find a number that is halfway between two fractions?
problem

Double With 1 to 9

Age

11 to 14

Challenge level

2 out of 3

Can you find a number and its double using the digits $1$ to $9$ only once each?
problem

Football Sum

Age

11 to 14

Challenge level

2 out of 3

Find the values of the nine letters in the sum: FOOT + BALL = GAME